BROOKSVILLE — On Thursday, Enrique Daniel Acevedo should have turned 20. He should have gotten a simple birthday gift, like new headlights or brakes for his car. He should have been surprised, yet again, with a homemade chocolate and vanilla cake his mother baked for him.

Instead, his family and friends, many of them wearing T-shirts adorned with his smiling face, sat and sobbed in a Hernando courtroom as Sabrina Dicus — one of three people accused of carjacking and killing Acevedo last year — pleaded guilty to second-degree murder.

"To go to court on his birthday, it took a lot," said his mother, Carmen Acevedo, after the hearing. "I hated it. I really hated it."

As part of Dicus' deal with the State Attorney's Office, the 16-year-old defendant agreed to testify for the state in future trials involving the slaying. That means she'll almost certainly be asked to take the stand against her mother, Sherrie Dicus, and former boyfriend, Steven Wesolek.

Prosecutors have said they are seeking the death penalty for Wesolek, whom they say actually killed Acevedo. Sherrie Dicus is facing a life sentence if convicted. Sabrina Dicus' maximum possible sentence will be capped at 30 years in prison if she honors the deal with prosecutors.

The three suspects, authorities say, murdered Acevedo, 18, and attempted to murder his friend, Skyler Collins, then also 18.

According to arrest affidavits, Acevedo and Collins drove to Emerson Road south of Brooksville on June 20, 2010, to pick up Wesolek, who was Collins' ex-boyfriend, and two of his friends.

After the three got into Collins' red 2001 Ford Mustang convertible, records say, Acevedo was stabbed twice in the back of the neck and Collins was choked until she lost consciousness. Collins reportedly regained consciousness when Acevedo slammed on the brakes, and the two stumbled out of the car near the intersection of Ayers and Culbreath roads.

Acevedo died on the side of the road as the car drove away.

In an interview with Hernando sheriff's detectives soon after she and the other two suspects were arrested just weeks after the murder, Dicus detailed what happened in the moments before and after Acevedo died.

Her mother, she explained, initially devised the plan to carjack Collins. The three only realized at the last moment that Acevedo would be coming with her.

Initially, she claimed her mother stabbed Acevedo and Wesolek attempted to strangle Collins. After detectives pressed her about making those statements to protect her boyfriend, she admitted Wesolek was the killer.

Still, she insisted, her mother devised the plot, describing it as a "foolproof plan" — Sherrie Dicus would strangle the girl, Wesolek would stab Acevedo, and Dicus would grab the steering wheel during the mayhem.

"My mom talked to Steven. It was my mom's plan," she said. "Steven went with it so he can get outta the bad situation."

With Wesolek behind Acevedo, Sabrina Dicus in the back middle seat and her mother behind Collins, Dicus said they prepared to attack.

"My mom gives the signal," she said.

"She did what?" asked Detective George Loydgren.

"She gave the signal."

"Well, what signal?"

"One, two, three."

"Okay," he said, "and then what happened when she got to three?"

"Well, since she convinced Steven to do it he did it," Dicus said. "She strangled 'em, I got the wheel."

At one point, Loydgren asked why the violence was necessary.

"Why would your mother come up with this diabolical plan to just kill somebody to take a car?" he asked. "Why not just tell the guy, 'Give me your car?' "

"Cause," Dicus responded, "(that) usually doesn't work."

During the Thursday morning hearing, Dicus frequently wiped tears from her eyes as prosecutor Pete Magrino described Acevedo's murder to the court.

After entering her plea, the teenager turned to the packed courtroom and looked at Acevedo's parents, Carmen and Danny, sitting in the front row.

"I'm sorry," she mouthed to them.

Carmen, crying and clutching her husband's hand, shook her head.

"Sorry doesn't bring my son back," she said later. "No words she can tell me can heal what I'm feeling."

John Woodrow Cox can be reached at jcox@sptimes.com or (352) 848-1432.